How to Make It
Prepare the Cornbread: Preheat oven to 425°F. Combine self-rising cornmeal mix and, if desired, sugar in a large bowl. Stir together eggs and buttermilk in a medium bowl; add to cornmeal mixture, stirring just until moistened.
Heat butter in a 10-inch cast-iron skillet in preheated oven 5 minutes. Stir melted butter into batter. Pour batter into hot skillet.
Bake in preheated oven until cornbread is golden, about 25 minutes; cool in skillet 20 minutes. Remove from skillet to a wire rack, and cool completely, 20 to 30 more minutes. Crumble cornbread. Freeze in large heavy-duty ziplock plastic bag up to 1 month, if desired. Thaw in refrigerator.
Prepare the Dressing: Preheat oven to 350°F. Cook 12 oz. chopped smoked sausage in a large skillet until browned and cooked through; transfer sausage to a paper towel with a slotted spoon to drain, and wipe skillet clean. Melt butter in the wiped-out skillet over medium-high; add onion and celery, and cook, stirring often, until tender, 10 to 12 minutes. During last five minutes of cook time, add the apples. Add sage and thyme, and cook, stirring often, 1 minute.
Stir together eggs in a very large bowl; stir in cooked sausage, crumbled Cornbread, onion mixture, stuffing mix, chicken broth, pepper, and salt until blended.
Spoon mixture into 2 lightly greased 13- x 9-inch (3-quart) baking dishes. Cover and freeze up to 3 months, if desired; thaw in refrigerator 24 hours. (Uncover and let stand at room temperature 30 minutes before baking).
Bake, uncovered, in preheated oven until lightly browned and cooked through, 1 hour to 1 hour 15 minutes.